# vim: tabstop=4 shiftwidth=4 softtabstop=4

# Copyright 2011 OpenStack LLC.
# Copyright 2010 United States Government as represented by the
# Administrator of the National Aeronautics and Space Administration.
# All Rights Reserved.
#
#    Licensed under the Apache License, Version 2.0 (the "License"); you may
#    not use this file except in compliance with the License. You may obtain
#    a copy of the License at
#
#         http://www.apache.org/licenses/LICENSE-2.0
#
#    Unless required by applicable law or agreed to in writing, software
#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
#    License for the specific language governing permissions and limitations
#    under the License.

"""RequestContext: context for requests that persist through all of nova."""

import copy
import logging

from heat.openstack.common import local
from heat.openstack.common import utils
from heat.openstack.common import timeutils

from heat.common import utils as heat_utils

LOG = logging.getLogger(__name__)


def generate_request_id():
    return 'req-' + str(heat_utils.gen_uuid())


class RequestContext(object):
    """Security context and request information.

    Represents the user taking a given action within the system.

    """

    def __init__(self, user_id, project_id, is_admin=None, read_deleted="no",
                 roles=None, remote_address=None, timestamp=None,
                 request_id=None, auth_token=None, overwrite=True, **kwargs):
        """
        :param read_deleted: 'no' indicates deleted records are hidden, 'yes'
            indicates deleted records are visible, 'only' indicates that
            *only* deleted records are visible.

        :param overwrite: Set to False to ensure that the greenthread local
            copy of the index is not overwritten.

        :param kwargs: Extra arguments that might be present, but we ignore
            because they possibly came in from older rpc messages.
        """
        if read_deleted not in ('no', 'yes', 'only'):
            raise ValueError(_("read_deleted can only be one of 'no', "
                               "'yes' or 'only', not %r") % read_deleted)
        if kwargs:
            LOG.warn(_('Arguments dropped when creating context: %s') %
                    str(kwargs))

        self.user_id = user_id
        self.project_id = project_id
        self.roles = roles or []
        self.is_admin = is_admin
        if self.is_admin is None:
            self.is_admin = 'admin' in [x.lower() for x in self.roles]
        elif self.is_admin and 'admin' not in self.roles:
            self.roles.append('admin')
        self.read_deleted = read_deleted
        self.remote_address = remote_address
        if not timestamp:
            timestamp = timeutils.utcnow()
        if isinstance(timestamp, basestring):
            timestamp = heat_utils.parse_strtime(timestamp)
        self.timestamp = timestamp
        if not request_id:
            request_id = generate_request_id()
        self.request_id = request_id
        self.auth_token = auth_token
        if overwrite or not hasattr(local.store, 'context'):
            self.update_store()

    def update_store(self):
        local.store.context = self

    def to_dict(self):
        return {'user_id': self.user_id,
                'project_id': self.project_id,
                'is_admin': self.is_admin,
                'read_deleted': self.read_deleted,
                'roles': self.roles,
                'remote_address': self.remote_address,
                'timestamp': heat_utils.strtime(self.timestamp),
                'request_id': self.request_id,
                'auth_token': self.auth_token}

    @classmethod
    def from_dict(cls, values):
        return cls(**values)

    def elevated(self, read_deleted=None, overwrite=False):
        """Return a version of this context with admin flag set."""
        context = copy.copy(self)
        context.is_admin = True

        if 'admin' not in context.roles:
            context.roles.append('admin')

        if read_deleted is not None:
            context.read_deleted = read_deleted

        return context


def get_admin_context(read_deleted="no"):
    return RequestContext(user_id=None,
                          project_id=None,
                          is_admin=True,
                          read_deleted=read_deleted,
                          overwrite=False)